An Introduction to VRLA Batteries1912957
VRLA batteries are upkeep free batteries. VRLA stands for Valve Regulated Lead Acid is the technical term for upkeep free batteries. VRLA batteries are also popularly called Sealed Maintenance Totally free batteries or SMF batteries in short.
VRLA batteries work on the oxygen recombination principle. The hydrogen and oxygen that are emitted in flooded lead acid batteries recombine in VRLA batteries to form water. That is why you do not have to add distilled water from outdoors as in the case of FLA batteries, which is what makes them upkeep free.
There are two primary kinds of VRLA batteries, gel cells and AGM. Gel cells add silica dust to the electrolyte, forming a thick putty-like gel. These are sometimes referred to as "silicone batteries". AGM, brief for "Absorbed Glass Mat", batteries function fibreglass mesh in between the battery plates which serves to include the electrolyte.
Nevertheless, the recombination procedure is not one hundred% effective. So over time, the released gases that have not recombined gather inside the VRLA therefore increasing the internal pressure, and have to be released to preserve the optimum stress. This is achieved with the assist of one-way, stress-sensitive valves which open when the internal pressure increases above a certain threshold and allow the excess gases to be vented. That is why these batteries are known as VRLA or valve regulated lead acid. Excess gases are also produced if these batteries are overcharged or discharged at rates higher than the recommended price.
The primary advantages of VRLA batteries compared to flooded lead acid batteries are:
- They do not create gases throughout regular operation or while charging and can consequently be kept in the vicinity of any electrical gear or any inflammable material, in contrast to FLA batteries.
- They do not emit acid spray even if charged abusively. Nevertheless, charging abusively will impact the battery life adversely and ought to be avoided at all costs.
- They are spill-proof and leak-proof.
- They can be used in horizontal position also which is some thing that you can't do with FLA batteries.
- They can be transported with out any restrictions:
- Surface transport: Classified as non-hazardous material as per DOT-CFR Title 49 components 171-189.
- Marine transport: Classified as non-hazardous material as per IMDG amendment 27.
- Air transport: Comply with IATA/ICAO, Special Provision A67.
The main disadvantages of VRLA battery compared to flooded lead acid batteries are:
- They offer lesser discharge currents compared to FLA batteries.
- They are much more costly compared to FLA.